1. Field of the Invention
The present invention relates to technical improvements for an electronic device having a housing for accommodating at least two batteries.
2. Description of the Related Art
There exist portable electronic devices such as digital cameras with a battery housing for accommodating a plurality of batteries that are intended to ensure a long-hour use of the device in question. The multiple batteries placed in the battery housing are typically connected in parallel by way of back-flow prevention diodes, thus supplying the relevant components of the electronic device with the power from the battery of a potential higher than that of any other battery housed inside. The technique based on the back-flow prevention diode arrangement causes a plurality of batteries to be tapped evenly for use. That means the batteries are exhausted at about the same time. This generally results in the inconvenience of having to replace (or recharge) the multiple batteries simultaneously.
The trouble above appears to be circumvented by the techniques proposed by Japanese Patent Laid-Open Nos. 2007-28738 and 2007-20335. The proposed techniques involve automatically selecting (i.e., extracting) one of a plurality of batteries in a battery housing on the basis of information about the output levels of the accommodated batteries. The multiple batteries in the battery housing are used one at a time according to the techniques, so that the batteries may be replaced (or recharged) in staggered fashion.